It may just be me, but for the last few champions and reworks Riot has done it felt like they were just... trying too hard to find new mechanics. A bunch of them were cool, like Quinn's bird-transformation, Graves getting a real shotgun, and the last few troll ults. But with Jhin it just feels kindof stupid, and doesn't feel as origional as Riot had intended. It's just his passive to me, everything else on his kit seems cool. He's a sniper with Graves' shell mechanic, he doesn't get attack speed, instead attack speed items give him ad, and crit gives him... movement speed? What exactly does that mean? Sure, we have no numbers to go on to see if it will be absurd or not, but it seems like Riot is making up for thematic creativity with hype and mechanics that will cause bugs through the entire season in his kit. My point is, it feels like Riot is trying too hard.
EDIT: This article wasn't meant to trash on the concept of giving new mechanics to new champions, it's just that it seems too much at one time. I like how with most of the preseason changes they diversified Marksmen without changing their inherent feel too much, and most of these changes feel rather cool and unique. However with Jhin it just feels dumb and unnecessary. His kit other than that passive, which has an entire paragraph of text explaining how it works, seems rather bland and rather simple, especially seeing the last few champions released/reworked like Bard, Ekko, new Poppy, and Tahm Kench (to a lesser extent). It just feels that Riot is cramming too many things into one ability and leaving the rest of his kit rather bland in a way that doesn't seem to have much synergy. My point is that it feels like Riot is being lazy by inserting lore that doesn't seem to match the champion and replaces it with hype and one mechanic that requires reading an entire instruction manual to make heads or tails of it.